Tuning pin for pianos



R. scHuLzE TUNING PIN FOR PIANOS March 23, 1937.

Filed Jan. 9, 1935 Patented Mar. 23, 1937 UNITED STATES PATENT OFFICE Claims.

My invention relates to a tuning pin around which one end of a piano string is wound to hold the same taut.

Such pins are subjected to a right angle pull 5 often in excess of one hundred and sixty-five pounds, and the total pull on the pin block is often in excess of sixteen tons. The pins are placed close together, and are of standard or uniform size, as generally used. To make the body, or part in the block larger would crowd the pins too much and not allow suflicient wood between adjacent pins to allow suificient strength of the block nor allow sufiicient hold of the pin in the block; to lessen the diameter weakens the 16 pin. To increase the size of the head makes the pin heads so close together that the tuning hammer or key is too near adjacent keys. Little variation in size is therefore possible. The pin often breaks near the head, where the wire hole 20 goes through at right angles to the body of the In tuning, the pin is generally turned a little beyond the point of proper tune for the string, and then turned back ever so little with the tun- 5 ing hammer for finally setting the pin and to even the pull on the wire, because the friction of the wire passing under the pressure bar and by the bridge pins is so great as to make the pull on the part of the string near the pin greater than that on the central part of the string. Also, during this operation the pin itself twists a little due to the great difference in the torsional resistance set up in the pin by the pin block and the pull of the tuning hammer, thus this slight :13 torsional twist is effectively used when turning the pin back by means of the tuning hammer for the final setting of the pin, thereby evening the tension on the whole string and arranging the molecules within the pin in a position of final in rest, tuning position, or pull on the wire.

The standard type of tuning pin which has been almost universally used heretofore in pianos, has a wire winding portion or neck that has a diameter substantially as large as the diameter of -13 the lower threaded portion of the pin which is threadedly positioned in the pin block. Due to this comparatively large diameter of the wire winding portion of the pin, the tightly pulled tuned wire has a tendency to cause the tuning 70 pin to turn back or slip in the pin block, due to the excessive winding diameter of the pin allowing too much torsional or leverage pull by the wire on the pin. For this reason the standard pin must be screwed or positioned in the wooden 55 pin block with such unusual tension as to often cause the block to split in the course of time. However, in spite of this precaution, these tuning pins have a tendency to slip unnecessarily and in a comparatively short time causing the piano to be out of tune. As may be readily seen, the introduction of this pin to the pin block with such excessive tension, makes the tuning of the piano very diflicult and uncertain due to the high torsional resistance of the pin, when any attempt is made to turn the pin either forward or backward in the tuning operation.

The important objects of any invention are first, to provide a tuning pin particularly adaptable to pianos, whereby, the wire winding portion of the same may be considerably reduced in diameter below that usually found in the standard type of tuning pin without in any way lessening the effective load carrying strength of the pin. By the proper reduction of this winding portion, the tightly drawn wire is brought close to the deadline or center of the pin proper, thus greatly diminishing the effective lever pull of the wire on the pin member, and reducing the chances of the pin being caused to slip or turn through the constantly pulling of the wire, and thereby greatly lengthening the time the piano will stay properly tuned. This reduced winding portion also allows for an increased winding leverage on the part of the pin, thereby allowing for more sensitive and finer tuning of the string, also this reduced leverage effect of the string on the pin allows the pin to be positioned in the pin block with less tension and incidentally with the possibilities of splitting the block in the usual manner reduced to a minimum.

Second, to make a pin with standard body and narrowed neck, to allow the same grip and diameter of body in the block, and to allow a greater leverage in holding the wire; also less force in the tuning operation is required because of the less diameter of the neck, and also the pulling wire tends less to turn the pin. The narrowed neck allows the pins to be placed closer together than usual, because the wire around the neck will not extend outwardly so far.

Third, to place the wire hole in a standard sized head at an oblique angle, which takes away less metal in the direction of twist of the tuning hammer on the head.

Fourth, to make the body a seamless tube, which provides greater tuning flexibility and allows the body to more readily twist itself in a torsional manner during the tuning operation, and also allows the pin to be settled back in a much easier manner by means of the tuning hammer to final torsional rest position during or at the final tuning operation, and thus in view of the reduced winding portion of the pin with less tension on the pin and pin block, the seam- 0 less body gives the pin more than the necessary strength needed to hold the required pull or load, particularly in view of the increased l verage of the pin brought about by the reduced winding portion or of the same.

10 Fifth, to make the hole in the body slope off gradually to substantially a point, or otherwise stated, the wall gradually increase in thickness as it approaches the solid neck, which prevents breaking of the pin below the neck. These and 15 other objects and advantages I obtain from the pin shown in the accompanying drawing in which,

Figure l is a front elevation of my new pin, Figure 2 is a side elevation thereof.

L Figure 3 is a cross sectional view thereof on line 3, 3 of Figure 1.

Figure is a cross sectional View of a piano block, showing the pin in operation.

In the drawing similar numerals refer to similar parts throughout the several views. The pin I has a head 2 of standard size and construction with four fiat surfaces for turning the pin with the tuning hammer. The body 3 is of the usual size and threaded. The neck l is of reduced diameter. The body may taper slightly toward its lower end, as shown, and it is drilled out, axially, leaving an opening 5 therein. The opening preferably stops a little short of the top of the body portion, so that the part of the pin that does not enter the block is solid, for strength. The top or" the hole tapers to nearly a point 6, which strengthens the merging of the hollow and solid portions of ti e pin. The hole preferably has parallel sides, so the tapering outside gives greater strength near the top of the body. The pin must have no seams in its body in order to stand the strain to which it is subjected.

At the juncture of the neck with the head, the hole I to hold the end of the wire goes oii at an oblique angle, rather than the usual right angle, and consequently, the head is not so likely to break oiT at this point.

The operation of the pin is shown in Figure 4, in which it is placed in the piano block 8, holding taut the wire 9, which passes under the pressure bar lfi, over the bridge ii on sounding board l2. The wire is reversely bent, offset by bridge pins l3, which cause considerable friction in tightening the wire.

In comparison with usual pins, it will be apparent that my new pin will hold the wire more tightly with less tension or grip on the block with a given load and is less likely to slip; it

may be placed closer to other pins; it will not be so likely to split the block and will not be so likely to break in two itself. It will also be apparent that the flexibility of the pin may be varied by making the axial hole larger or smaller.

What I claim as new is:

l. .A metallic tuning pin for pianos and like instruments comprisin a body portion substantially the whole length of which is adapted to be placed in and held by the pin block of the instrument, a head shaped for turning the pin by a tuning hammer, a neck between said body portion and head for the winding of the string therearound, said neck having a smaller diameter than the body portion, and a string hole beginning in the neck near the head and passing a substantial distance obliquely into the head.

2. A metallic tuning pin for pianos and like instruments comprising a body portion substantially the whole length of which is adapted to be placed in and held by the pin block of the instrument, a head shaped for turning the pin by a tuning hammer, a. neck between said body portion and head for the winding of the string therearound, and a string hole adjacent the juncture of the neck and head and passing a substantial distance obliquely into the head.

3. A metallic tuning pin for pianos and like instruments comprising a seamless tubular body portion substantially the whole length of which is adapted to be placed in and held by the pin block of the instrument, a head shaped for turning the pin by a tuning hammer, a solid neck between said body portion and head for the winding of the string therearound and a string hole in the neck.

4. A metallic tuning pin for pianos and like instruments comprising a seamless tubular body portion substantially the whole length of which is adapted to be placed in and held by the pin block of the instrument, a head shaped for turning the pin by a tuning hammer, a solid neck between said body portion and head for the winding of the string therearound, the wall of the body portion tapering gradually into the solid neck. and a string hole in the neck.

5. A metallic tuning pin for pianos and like instruments comprising a tubular body portion substantially the whole length of which is adapted to be placed in and held by the pin board of the instrument, a head shaped for turning the pin by a tuning hammer, a solid neck between said body portion and the head for the winding of the string therearound, said neck having a smallor diameter than the body portion, and a string hole in the neck.

REINHARD SCHULZE. 

